Lasers are commonly used as the source of light signals in optical communications systems. These lasers are often integrated onto optical chips and/or onto optoelectronic chips. The laser cavities in these lasers often include a partially reflective optical grating positioned at one end of the laser cavity. These gratings are configured to transmit a portion of the light signal generated in the cavity and to return another portion of the light signal to the cavity. The returned portion of the light signal amplifies and is later transmitted by the grating as the laser output. These gratings are generally configured to reflect light in a very narrow range of wavelengths in order to limit the laser output to a single wavelength or to a single mode.
One of the challenges with these lasers is mode hopping. Mode hopping refers to the light signal produced by one of these lasers changing from one mode to another. The change between modes is associated with an undesirable change in the wavelength of the light signal output by the laser. The mode hopping can be a result of influences that change the index of refraction of the media through which the light signals are guided during amplification. Examples of influences that can cause these effects are temperature changes and/or changes in the level of electrical current applied to the media through which the light signals are guided. In order to address these problems, many of these devices include temperature control devices and/or other feedback control devices for stabilizing the indices of refraction of the media through which the light signals are guided. These temperature control devices and/or other feedback control devices increase the complexity and/or cost of the device.